Here's how I do it for 1 adult 2 dc and 2 cats on about £65 a week:
£13 on organic fruit veg/box every week
£100 at Sains about every 4 weeks when I spend about £30 on wine to last a month or more
£40 or so at Aldi about every 4 weeks
Top-ups at Sains x 2 per 4 weeks, about £20 a time
£20 or so at the farmers market every 4 weeks for eggs, good meat
This includes all household stuff, cat food,loo roll etc and probably some clothes, presents, etc too. I always buy organic milk and free range eggs/meat. I take lunch to work, dc vary - sometimes one or both having school dinners but I think I might spend an extra £40 a month on the above if both having packed lunch.
I do bulk buy things on offer, esp. non-perishables of course, like loo roll and cat food. Eat little meat, but buy reduced items (on best before day) like mince, chops, etc and freeze them.
I've always tried to budget and live frugally but now it is a necessity - don't think I can save much more without compromising my ethics or selling the dc cats. You will never take my real coffee away!
Things I generally do without now are crisps, nuts, fruit juice, treats/biscuits of any kind.